The only thing I did to modify the pattern is add some hair for the minions and I added a three row border at the bottom. The border is made starting from the back seam: 1sc, ch 2, 1sc in nearest "valley", ch 2, 1sc in nearest "valley", ch 2, etc.

Below are links to the PDF files I created to make the minion beanies. The yellow beanie chart is baby sized (6-18 months) and the purple charts are sized for a smaller child. But it is easy to add rows to the top and bottom and columns to the left and right of the charts, so making them in a larger size should be no problem.

Click on the images below to go to the corresponding PDF file (NOTE: These are just the plain charts, you'll need The Graph Beanie pattern to make a beanie from a chart):